I think the clue is that Israel is never referred to as 'he' in such contexts.
If that's meant to be an argument, it's worse than threadbare. If it had anything going for it, you'd have to assume the sudden switch of identity occurred between Isaiah chapters 41 and 42.
In Isaiah 41 we read:
"[8] But you, Israel, my servant,
Jacob, whom I have chosen,
the offspring of Abraham, my friend;
[9] you whom I took from the ends of the earth,
and called from its farthest corners,
saying to you, "You are my servant,
I have chosen you and not cast you off";
and in chapter 42:
[1] Behold my servant, whom I uphold, my chosen, in whom my soul delights;
I have put my Spirit upon HIM,
HE will bring forth justice to the nations.
I suggest that Isaiah 52 - 53 were just texts used to source the narrative and theology of the NT, just as so many other OT texts appear to have been used for this purpose, without there being much actual history to corroborate the details. Those details being somewhat meagre: Jesus went around preaching and teaching, and was crucified.